Transcript File

Pedigree Charts
The family tree of genetics
What is a Pedigree?
A
pedigree is a chart of the genetic
history of family over several
generations.
 Scientists
or a genetic counselor would
find out about your family history and
make this chart to analyze.
Constructing a Pedigree
 Female
 Male
Symbols in a Pedigree Chart
 Affected
(expressed)
 Deceased
(doesn’t necessarily mean
the “trait” is what killed them)
or
or
Connecting Pedigree Symbols
Examples of connected symbols:
Married
Couple
Siblings
Pedigree Charts
I
II
III
Example
 What
like?
does a pedigree chart look
Interpreting a Pedigree Chart
2.
Determine whether the disorder is
dominant or recessive.
– If the disorder is dominant, one of
the parents must have the
disorder.
– If the disorder is recessive, neither
parent has to have the disorder
because they can be heterozygous.
Example of Pedigree Charts
 Is
the trait Dominant or Recessive?
Answer
 Dominant
Example of Pedigree Charts
 Dominant
or Recessive?
Answer
 Recessive
Summary
 Pedigrees
are family trees that
explain your genetic history.
 Pedigrees are used to find out the
probability of a child having a
disorder in a particular family.
 To begin to interpret a pedigree,
determine if the disease or condition
is autosomal or X-linked and
dominant or recessive.